Date: Wed, 16 Sep 92 05:04:06 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #207 To: Space Digest Readers Precedence: bulk Space Digest Wed, 16 Sep 92 Volume 15 : Issue 207 Today's Topics: Asteroid explorer Is NASA really planning to Terraform Mars? (2 msgs) Magellan Begins Gravity Mapping of Venus plantary formation Pluto Direct Propulsion Options (2 msgs) Population (2 msgs) Probes - self portraits? Problems answering people from The Federation. QUERY Re: Pluto Direct/ options TOPEX Update - 09/14/92 Who went to Rio? Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: 15 Sep 92 20:41:58 GMT From: Nick Szabo Subject: Asteroid explorer Newsgroups: sci.space,sci.astro,alt.sci.planetary [Phil posts neat idea for hitting asteroid with a tank and measuring the seismic effect] Along these lines, perhaps we can steer upper stages headed for deep space into intercept trajectories, and get some observing time on a big telescope like Keck or Hubble to see what happens. For example, could Mars Observer's TOS be steered into Phobos, or would we have had to tinker with TOS's navigation box beforehand? Do we know Phobos' orbit well enough to steer blind? What could we learn by doing imaging and spectroscopy on the resulting Phobos debris cloud? I suspect this would be a great way to learn what lies underneath the surface layer of regolith. The collision wouldn't damage Phobos, just put another impact crater on it. Some future isotopic ratio studies might be effected, and the spectroscopy study itself would have to factor out the TOS debris. -- szabo@techbook.COM Tuesday, November third ## Libertarian $$ vote Tuesday ^^ Libertarian -- change ** choice && November 3rd @@Libertarian ------------------------------ Date: 15 Sep 92 14:01:27 GMT From: Gary Coffman Subject: Is NASA really planning to Terraform Mars? Newsgroups: sci.space In article jbh55289@uxa.cso.uiuc.edu (Josh 'K' Hopkins) writes: >dietz@cs.rochester.edu (Paul Dietz) writes: >>Your non sequitur appears to be the following: If there is >>overpopulation, then people would starve. People are starving. >>Therefore, there is overpopulation. > >I think my question was legitimate. Do you believe the situation is going to >improve as population gets larger? I'm not so worried about "overpopulation" >per se. What I do believe is that allowing people to have control of the >number of children they raise will result in a lower growth rate, which I >believe to be an improvement. Two things. As world population has grown, both the percentage and the absolute numbers of malnurished people have diminished. I won't attempt to imply causation here, just reporting the fact. The second thing is more to the point. In subsistence agricultural communities with poor health care and a non-existant social safety net, having more children is an *advantage* for the people. The high birth rate makes up for the high infant mortality rate and provides them with additional laborers in the fields and a fairly large group of descendants to take care of them in their old age. Merely providing birth control without also supplying these other necessities would be doing these people a disservice. Farm family size in the US has decreased as mechanization and social services have improved. This is also true of non-farm families. The shortage in subsistence communities is almost always labor. Only 6% of the arable land in Africa is farmed. That's because there isn't enough labor available to productively use the land with pre-industrial techniques. Using standard Green Revolution techniques, Africa should easily be able to increase it's yield of foodstuffs by 40 times it's current production. Minus the effects of tribal warfare, current farm production in Africa is sufficient for the current population. This isn't meant to imply that increasing Africa's population by 40 fold would necessarily be a good thing, but it is possible for them to feed that many with known techniques. Gary ------------------------------ Date: 15 Sep 92 19:18:30 GMT From: Paul Dietz Subject: Is NASA really planning to Terraform Mars? Newsgroups: sci.space In article <1992Sep15.140127.3073@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes: > The shortage in subsistence communities is almost always labor. Only > 6% of the arable land in Africa is farmed. That's because there isn't > enough labor available to productively use the land with pre-industrial > techniques. Using standard Green Revolution techniques, Africa should > easily be able to increase it's yield of foodstuffs by 40 times it's > current production. Actually, about 30% or so of the arable land in Africa is currently farmed (the 6% figure refers to one of the countries where food prices are being held artificially low.) Africa has about twice as much arable land as the far east, but has a lower population. There are two major problems with African agriculture. The first is that the soil is mostly poor. Unlike the temperate regions, the soil has been leached for millenia by tropical rains without replenishment from glaciation (which grinds up nutrient-rich bedrock and spreads it across the land). African soils are often red and acidic, and in some places nutrient mining is occuring, with declining yields. The upside of this is that the land responds readily to fertilizer, properly applied. The second problem is that 80% of farming in Africa uses manual labor; not even animal labor (due to the tsetse fly). This is the reason for the unused land; a family can farm only about 2 1/2 acres without animals. The Op-Ed page of the NY Times yesterday (9/14/92) had a piece on Dr. Norman Borlaug (1970 Nobel Peace Prize winner for hybrid wheat, which has helped China to become the world's leading grain producer and India to quintuple wheat production since 1967), who is trying to get Africa to use existing knowledge on fertilizers, plant varieties, pest and moisture management. His team has applied this knowledge to 150,000 farms in Africa, increasing the yield by an average of 2.5 times. Borlaug started in 1986 with wheat and sorghum in the Sudan and maize in Ghana. Ghana's maize production is up 40%; wheat production in the Sudan increased from 160,000 tons in 1986 to 800,000 tons in March of this year. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 16 Sep 92 04:37:18 GMT From: Ron Baalke Subject: Magellan Begins Gravity Mapping of Venus Newsgroups: sci.space,sci.astro,sci.geo.geology,alt.sci.planetary Michael Braukus Headquarters, Washington, D.C. September 15, 1992 (Phone: 202/358-1547) Jim Doyle Jet Propulsion Laboratory, Pasadena, Calif. (Phone: 818/354-5011) RELEASE: 92-148 NASA SPACECRAFT BEGINS GRAVITY MAPPING OF VENUS The Magellan spacecraft's orbit at its closest approach to Venus was lowered Monday and today it began a full 243- day cycle of gravity mapping, project officials at NASA's Jet Propulsion Laboratory, Pasadena, Calif., said. Magellan has now completed three cycles of mapping with its radar, covering 99 percent of the surface of Venus. Monday, controllers ordered a 1-hour orbit adjustment burn to lower its periapsis -- closest approach to the planet -- altitude from 160 miles (258 kilometers) to 113 miles (182 kilometers). "That will help us obtain the best possible resolution in the equatorial latitude gravity map," Project Manager Doug Griffith said. The objective of cycle 4, which extends to May 15, 1993, is to obtain a global map of the Venus gravity field from the elliptical orbit. The orbit apoapsis, or furthest point from the planet, remains the same, 5,296 miles (8,543 kilometers). During this fourth cycle, variations in the gravitational pull experienced by the spacecraft are being recorded by carefully tracking the Doppler shift of a radio signal that Magellan will constantly beam to the Deep Space Network tracking stations. When Magellan passes over a dense region of Venus' interior, for example, the spacecraft accelerates in its orbit and the location of the denser region is mapped. Over the course of the 243-day cycle, one rotation of Venus, variations in the planet's density will be mapped at a resolution much higher than achieved by previous missions. Looking at the interior with gravity observations is expected to provide an improved understanding of the forces of tectonics and volcanism that shape the planet. Magellan is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science and Applications, Washington, D.C. - end - ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Quiet people aren't the /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | only ones who don't say |_____|/ |_|/ |_____|/ | much. ------------------------------ Date: 15 Sep 92 19:34:29 GMT From: Marc Allan Rouleau Subject: plantary formation Newsgroups: sci.astro,sci.physics,sci.space I am working on a project here at WPI to examine theories on the origin of the solar system. Can anyone suggest some good books, articles, etc. In particular I am interested in the particular distribution of the planets' masses - large in the middle and progressively smaller towards the ends (or more or less so). Thanks. Marc A. Rouleau rouleau@wpi.wpi.edu ------------------------------ Date: 15 Sep 92 20:16:10 GMT From: Nick Szabo Subject: Pluto Direct Propulsion Options Newsgroups: sci.space In article pgf@srl02.cacs.usl.edu (Phil G. Fraering) writes: >henry@zoo.toronto.edu (Henry Spencer) writes: >(I can hear them now. "Eeek! deployable! Ever since Galileo, we're not >supposed to use deployable structures until hell freezes over! We're >supposed to be stuck with whatever can fit inside the payload shroud >until the end of time!" Why not just _not_ drive the probe across the >country half a dozen times before launch?) Well said. Note that the TDRSS's had the same kind of deployable antenna as Galileo, and they unfolded without a hitch. In fact, there have been dozens of successful automated deployments on all kinds of spacecraft, from spysats to comsats, most in places where astronauts cannot go. -- szabo@techbook.COM Tuesday, November third ## Libertarian $$ vote Tuesday ^^ Libertarian -- change ** choice && November 3rd @@Libertarian ------------------------------ Date: Tue, 15 Sep 1992 20:13:12 GMT From: Dave Tholen Subject: Pluto Direct Propulsion Options Newsgroups: sci.space,sci.astro Ian Taylor writes: > My understanding is that our current knowledge about Pluto is minimal, is it > established that Pluto even has an atmosphere? Absolutely. The 1988 stellar occultation experiment is the evidence. Check out Elliot et al. in, if I remember correctly, the first 1989 issue of Icarus. ------------------------------ Date: 15 Sep 92 18:18:09 GMT From: Doug Mohney Subject: Population Newsgroups: sci.space Reply-To: sysmgr@king.eng.umd.edu Organization: Computer Aided Design Lab, U. of Maryland College Park Lines: 60 Sender: news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU In article , jbh55289@uxa.cso.uiuc.edu (Josh 'K' Hopkins) writes: [ in the truest sense of out of control topic growth.....] >First, I'd like to point out that I'm not the same person who wrote the follow >up to my post, nor do we agree on all things. Doug lumps us togther. Since >the mid 80's, America has stopped giving moneyt to the UN agency that works to >combat population growth in the third world. We stopped giving money to UNESCO, the educational and cultural part of the UN, along with a lot of other folks, because they were gold-plating their office in France. Literally. They started getting their act together, so the taps have been open. The Reagan adminstration stopped giving money to some non-UN organizations which were "promoting" abortion as a means of birth control. >Come to think of it, I believe we don't give the UN any money anymore. We give them money. We don't give them as much money as we owe them; I think we're back-debted at least $300-450 million; don't have a ready reference for that here. > Anyway, my point is the following, >given that there is an unfulfilled demand for birth control (I don't think I've >cited sources here, but if you want I'll dig some up) and that population >growth in the third world tends to eat up progress made by foreign aid, This was one of these paradoxes of the 60's and 70s. We provided modern health care first in the form of vaccinations and other (minor for First world) improvements without anticipating the growth in number of mouths to feed. ANYwhooo, there are any number of organizations, both publically and privately funded, which are providing family planning/birth control information and aid to these places. However, until you reduce the incentives for big families through economic growth (i.e. turn 'em into capitalists :-), the individual family is going to continue to have kids. UN(?)fortunately, the spread of AIDS is going to adversely affect the Third World. Serious war going on to promote condom usage, which may (should) also check population growth. Unless condoms aren't used, in which case population growth will (alas) be checked by biological means. >But transitions take a while. The people who are working on electric vehicles, >which may eventually be quite competitive with gas powered ones, or solar >thermal power, or finding ways to _save_ money through conservation are doing >it because it's a good investment. The substitutes you're talking about are >being worked on now, but you're slamming them. I am not slamming substitutes. I am slamming crash programs to throw money at problems which, as the Synfuels debacale of the Carter Administration showed, doesn't really work. But, how we solve the problems of the world rather than NASA is drifting wayway way down the yellow brick road. Play in the intelluctual sandbox of Usenet -- > SYSMGR@CADLAB.ENG.UMD.EDU < -- ------------------------------ Date: 15 Sep 92 15:04:42 GMT From: Gary Coffman Subject: Population Newsgroups: sci.space In article jbh55289@uxa.cso.uiuc.edu (Josh 'K' Hopkins) writes: > >First, I'd like to point out that I'm not the same person who wrote the follow >up to my post, nor do we agree on all things. Doug lumps us togther. Since >the mid 80's, America has stopped giving moneyt to the UN agency that works to >combat population growth in the third world. Come to think of it, I believe >we don't give the UN any money anymore. Indeed we are fully paid up members again since Desert Storm. The US had been withholding $425 million dollars in dues to the UN prior to the war, but when the SC came through and backed the US, we coughed up the money. > Anyway, my point is the following, >given that there is an unfulfilled demand for birth control (I don't think I've >cited sources here, but if you want I'll dig some up) and that population >growth in the third world tends to eat up progress made by foreign aid, it makes >sense to help reduce growth - where the assistance is desired - instead of >sending cash. I then went on to suggest that lowering growth would be more >likely to help stabilize the region that not lowering growth. In most subsistence cultures there is *no* demand from the indigenous population for birth control. Indeed, extra hands are the only resources that they can produce. There is a labor *shortage* in Africa, and most of the rest of the third world. This may seem surprising, but it's true. The low productivity of labor without benefit of mechanical and technical amplification is such that many many hands are needed for the most basic jobs. In some parts of Africa, farmers still use wooden digging sticks. A modern (19th Century) steel moldboard plow would make more difference to these people than any amount of birth control equipment. [re: transistion from an oil economy] >But transitions take a while. The people who are working on electric vehicles, >which may eventually be quite competitive with gas powered ones, or solar >thermal power, or finding ways to _save_ money through conservation are doing >it because it's a good investment. The substitutes you're talking about are >being worked on now, but you're slamming them. Electric vehicles aren't what's being talked about here. At $35 a barrel equivalent, alcohol produced from biomass is economical with known and tested techniques available *now*. At $55 a barrel equivalent, Fischer- Topish (sp) process synthetic gasoline from coal or shale is economical and feasible with techniques known and tested in volume production over 50 years ago. As the price of oil eventually rises, there are known, developed, and available alternative liquid fuel technologies that will come on line to take the place of oil. This is a solved problem. Electric vehicles are touted for two main reasons. One, they have low point of *use* emissions. And two, they are the ultimate multi-fuel vehicle since any fuel that can be used to make electricity can power them. However, the storage battery problem remains intractable after over a century of development. Electric vehicles, if they become common, will be externally powered or have short range and a limited performance envelope until the battery problem is licked. I don't hold out much hope that a miracle battery is on the horizon that will change this. Battery science is as complex, if not more so, as rocket science. Rocket science hasn't delivered cheap payload of orbit, and battery science hasn't delivered cheap, light, high capacity batteries. Some here would claim that that's *because* of government funded research, not in spite of it. Gary ------------------------------ Date: Tue, 15 Sep 92 19:41:16 GMT From: Joshua Bell Subject: Probes - self portraits? Newsgroups: sci.space I've often wondered, especially in the wake of Gallileo's stuck HGA, but also after Voyager 2 headed off into never-never land past Neptune, why the cameras on these craft are unable to be located so that they can take images of the craft itself, for self-diagnosis, and also for PR - I would have LOVED a rather non-scientific shot of Voyager 2 looking back over its own shoulder towards Neptune, or during the fly-by, so we can see the various parts of the craft. Venera landers returned pictures of their own shadows (I'm sure others did as well, but I remember the Venera pic best), and Viking was designed to look at parts of itself (eg, the color bar, the sample arm, etc) - is there no hope for non-lander probes? Must we be content with the animation (I'm still in awe of James Blin's [did I spell it right?] Voyager 2 animation tho. :) Joshua | Tremble only if you build false accounts and stand pridefully upon them | | - Lord Leto II, God Emperor of Dune | | | | jsbell@acs.ucalgary.ca Academic Computing Services, University of Calgary | ------------------------------ Date: 15 Sep 92 15:15:05 GMT From: asljl@acad2.alaska.edu Subject: Problems answering people from The Federation. Newsgroups: sci.space Path: acad2.alaska.edu!asljl From: asljl@acad2.alaska.edu Newsgroups: sci.space Subject: The Federation is still here Message-ID: <1992Aug11.155953.1@acad2.alaska.edu> Date: 11 Aug 92 15:59:53 AST Organization: University of Alaska Lines: 34 Path: acad2.alaska.edu!asljl From: asljl@acad2.alaska.edu Newsgroups: alt.alien.visitors Subject: The Federation is still here Message-ID: <1992Aug11.155325.1@acad2.alaska.edu> Date: 11 Aug 92 15:53:25 AST Organization: University of Alaska Lines: 25 Hello All Yes, The Federation is still here, at the moment for those still interested, it is still here and still reachable. We still want to hear from people interested in it or new people interested in the Federation. For those of you who are new to the Federation ideas, this is what we are: We are a group of people who feel it is high time we got off this rock and started exploring the great unknown of space. We have drawn out in blue print form a drive system that is a a super semi conducting crystaline structure. It looks good on paper but we haven't been able to test it yet. As always the problem is money. The Federation has been working on a personal funds of the few members base at the moment. We do have a info packet that we will happy to give you. You must have a mac that has 5.0 microsoftword or better. Send us a 3.5 floppy and we will put it on there for you. send to this adrress The Federation C/O Lady Rhavyn Po box 231772 Anchorage, Alaska 99523-1772 If you have any questions feel free to send to this account. ASLJL@ACAD2.ALASKA.EDU ******************************************************************************** I have had a problem sending the small version of the Federation Manual overthe E - Mail system. It seems it does not like some the of the addressesI am using that people send me. Please be sure that you include in your E-mail request, your internet/bitnet E-mail address so that I have the correct address to send it to you. My problem has been that I have had to, on occassion take it off the beginning of your messages. Either I am not copying it down correctly or the computer is scrambled, or it does not like the address and so I get a message from the postmaster telling me it doesn't like that address. I do apologize to those of you who asked for the info and never received it. Please try again. Member of the Federation * May the Force be With You * Thank you Sincerely Lady Rhavyn Memeber of the ------------------------------ Date: 15 Sep 92 20:22:54 GMT From: Dave Tholen Subject: QUERY Re: Pluto Direct/ options Newsgroups: sci.space Mark Brader writes: > Several slingshot trajectories have been proposed as alternatives to the > direct Pluto flight, but not the one that I would have thought obvious: > a simple Jupiter slingshot. Jupiter should be in the right position > for a period of, I would guess, some weeks or months, at intervals of > about 12 years. The Jupiter slingshot has, I can assure you, been proposed. Yes, Jupiter is in the right position about every 12 years, but the interval can be as long as two years. If you go for the earliest opportunity, the bending angle at Jupiter is rather severe, requiring a very close approach, and consequently lots of radiation shielding. This essentially sets the limit for how early one can use Jupiter for a gravity assist. At the late end, you're limited by the law of diminishing returns: little bending angle, little gravity assist. The next Jupiter alignment that could be used for a Pluto mission is in the 2002 to 2004 time frame, and that was the window the Outer Planets Science Working Group had its eye on before Goldin took over as NASA Administrator. He favored a "faster, smarter, cheaper, sooner" approach, and that's when direct trajectories were given more serious consideration. ------------------------------ Date: 16 Sep 92 04:33:53 GMT From: Ron Baalke Subject: TOPEX Update - 09/14/92 Newsgroups: sci.space,sci.geo.meteorology Forwarded from: PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109. (818) 354-5011 TOPEX/POSEIDON STATUS REPORT September 14, 1992 The TOPEX/Poseidon satellite is performing nominally and is healthy. Attitude control, solar array, batteries, telecommunications, and the on-board computer are all functioning normally. In-Plane Maneuver #3 was performed successfully today. This was the first burn performed using the four, small 1 Newton thrusters. The next TRIM Maneuver is scheduled for Monday, Sept. 21. The NASA altimeter remain in idle mode while the SSALT is in track mode. The SSALT will be turned off today and the NASA altimeter will be commanded to track. Over the weekend, the SSALT had near overflights of both the NASA and CNES verification sites. Also, the SSALT overflew hurricane Iniki on several orbit passes over the Pacific Ocean. Before it was put into idle mode, the NASA altimeter recorded 24-foot waves in the Pacific, presumably due to the hurricane. Project engineers are analyzing why the Global Positioning System Data Recorder failed to come out of idle mode today when it was commanded to track. Over the weekend the GPSDR memory was reloaded, readout, and a checksum was verified. The satellite is now sharing TDRSS resources with the shuttle. TDRSS support continues to be excellent with no significant impact to our mission. ###### ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Quiet people aren't the /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | only ones who don't say |_____|/ |_|/ |_____|/ | much. ------------------------------ Date: 15 Sep 92 21:11:09 GMT From: Nick Szabo Subject: Who went to Rio? Newsgroups: sci.space In article <1992Sep14.054546.1@fnala.fnal.gov> higgins@fnala.fnal.gov (Bill Higgins-- Beam Jockey) writes: > >At the moment, "moving some industry off Earth," as a method of >"saving the environment," must be viewed as pure science fiction. It is, however, a valid response to "look at all the exponential growth of this and that, we're going to destroy our planet in a hundred years!", which is also science fiction. -- szabo@techbook.COM Tuesday, November third ## Libertarian $$ vote Tuesday ^^ Libertarian -- change ** choice && November 3rd @@Libertarian ------------------------------ End of Space Digest Volume 15 : Issue 207 ------------------------------